A game of Civ, stripped down to its essentials, means collecting the little
,
,
counters up off the map and using your cities to turn them into STUFF. STUFF wins you the game. More
+
+
= more STUFF = more chance of win. So throwing away some would be the game letting you be stupid, so it doesn't let you.
In the past many have suggested, and modded in, the ability to bank the
from a city and use them later, which is what perhaps you're suggesting rather than just throwing them away. I think the reason that's not in the main game though is because (a) it trivialises the wonder system (i.e. insta-build wonders) and (b) to a lesser extent it makes it too easy to build a quick army when you get a brief tech lead.
But anyway at the start of the game what are you talking about there's nothing to build????!!! If nothing else, trust me, you DO need more workers